Virgin does not recognise the PPU, which represents around 450 of its 800 pilots, and chooses to negotiate instead with the British Airline Pilots Association, or Balpa.

Outgoing Virgin Atlantic chief executive Craig Kreeger wrote to pilots last week to explain changes to the terms and conditions of their employment, the Financial Times reports.

These changes include capping income protection, cancelling a dependants’ pension scheme, and reducing corporate pension contributions.

The PPU in a statement issued on Thursday (November 8) branded the move a “cost-cutting exercise”.

PPU spokesperson Steve Johnson, a former senior Virgin Atlantic captain, said: “Our efforts to take part in the benefits review have been repeatedly resisted by the company.

“Our members have mandated the PPU to negotiate, but for the last two years it appears the company has chosen to ignore the majority of its pilots and deal only with a union that speaks for the minority. That’s a fundamental mistake.”

A Virgin Atlantic spokesperson said: “We have been working closely with our recognised trade union Balpa in relation to a proposal regarding a benefits review, and are confident that this will be completed in a satisfactory manner.

“We’ve always been willing in principle to recognise the PPU, but we won’t agree to their demand that we derecognise Balpa, and disenfranchise the hundreds of pilots who belong to this union.”

Balpa says it has rejected Virgin’s initial proposals, but is not considering industrial action at this stage. The PPU, meanwhile, says the changes form part of a broader dispute with the airline, including recognition, and would ballot members.

Johnson said he recognised a strike around Christmas would cause “considerable upset”, adding his ambition would be to avoid industrial action through negotiation.